Base for chairs



FIG. 1 is a bottom perspective view of the base for chairs embodying my design;

FIG. 2 is a front elevational view of the base for chairs, the back view being identical;

FIG. 3 is a left side elevational view of the base for chairs the right side being identical;

FIG. 4 is a top plan view of the base for chairs; and,

FIG. 5 is a bottom view of the base for chairs. 

The ornamental design for the base for chairs, as shown and described. 